Mr. Jones had amassed millions of followers, but limiting his influence does not solve the problem of false news. Hundreds of smaller publishers promote similar conspiracy theories, and millions of followers help spread those theories by reposting them. A new conspiracy theory called Qanon, for instance, has been gaining traction outside of Mr. Jones’s sphere. And Infowars followers can also still repost videos and articles from the site onto YouTube and Facebook.

But the moves are a significant hit to Mr. Jones’s ability to reach wide audiences, and particularly new followers. YouTube was a particularly important distribution channel, in part because YouTube’s recommendation engine frequently surfaced past Infowars videos to users who had shown interest in conservative topics. Terminating his YouTube channel erases all of its past videos and restricts it from posting new ones.

Mr. Jones and Infowars still have other ways to reach listeners and readers. They have increasingly been directing viewers to visit the Infowars website, which would limit their reliance on the tech companies, presumably foreseeing the bans. Twitter has not restricted the accounts of Mr. Jones or Infowars. A Twitter spokesman said the accounts were not in violation of Twitter’s rules.

Other tech companies’ approach has been uneven; they have left up Infowars content on some of their services despite removing it from others.

Infowars introduced a new smartphone app last month that is finding users on Apple’s App store and Google’s Play Store. From July 12 through Monday, the Infowars app was, on average, the 23rd most popular news app on the Google Play store and the 33rd most popular news app on Apple’s App Store, according to App Annie, an app analytics firm. On Monday, the Infowars app ranked ahead of apps like BuzzFeed and The Wall Street Journal on Google, and ahead of apps like MSNBC and Bloomberg on Apple.

Apple decided to allow the Infowars app on its store after reviewing it, according to a person close to the company who spoke on condition of anonymity. The Google Play Store has different policies than YouTube, a Google spokesman said.

Matt Rivitz, a freelance copywriter who helps run a Twitter account, Sleeping Giants, that pressures companies to distance themselves from far-right groups, said Monday that the tech companies’ nearly simultaneous moves against Mr. Jones proved they were acting in response to public pressure, not new data showing he broke rules.